Excel sees a substantial improvement, with the re-introduction of VBA (Visual Basic for Applications). This was probably the most significant omission from Office for Mac 2008, to the extent that we know at least a few corporate users who were unable to upgrade without losing necessary functionality in their spreadsheets. While Microsoft admits there still isn't 100 per cent compatibility between VBA in Excel on Mac and Windows, everything else - conditional formatting for example - should work perfectly.
If you're a long-time user of Office for Mac, the change you'll really be welcoming, and to which we've already alluded, is the removal of Entourage, to be replaced with Outlook. It's a victory not just for consistency of applications, but also for the sanity of those trying to use a Microsoft email system with a Mac.
Features such as a unified folders (all your inboxes in one place, for example), a conversation view for emails, and integration with Time Machine all add up Outlook being a massive improvement over Entourage. Those points notwithstanding, however, Microsoft is still aware that a dedicated email client isn't exactly necessary for Mac users - Mail is pretty darned good for a built-in application - so if you just want PowerPoint, Excel and Word you only have to pay for them.
If all that sounds exciting, then bear in mind that we barely scratched the surface of what's on offer in our brief hands-on time with Office for Mac 2011; if the documentation supplied with our review copies is anything to go by, there's a lot more in store for us to discover in our full review. We'd get to the homepage and start mashing F5 if we were you.